Known sender, new behavior
A familiar contact unexpectedly changes payment details, file services, tone, urgency, or the type of information requested.
Email Account Compromise Awareness
How to Recognize and Report Email Account Compromise
Email account compromise occurs when an unauthorized person gains access to a mailbox and uses its messages, contacts, identity, or settings.
Use this guide to turn the threat into a clear employee decision, a safe practice scenario, and a reporting step your organization can support.
Plain-English definition • Warning signs • Safe simulation ideas • Reporting practice
01Understand the threat
Email Account Compromise: a practical definition
Email account compromise occurs when an unauthorized person gains access to a mailbox and uses its messages, contacts, identity, or settings.
A message from the compromised account can have a genuine address and authentic conversation history. Sender familiarity alone is therefore insufficient for payments, secrets, access, and sensitive data.
Source: CISA Phishing Guidance
02Recognition clues
Warning signs employees can check in a email account compromise message
No single clue proves that a message is malicious. Teach employees to combine the request, sender, business context, destination, and available verification route before acting.
Mailbox-setting notices
The user sees unexplained forwarding, rule, recovery, delegate, or sign-in changes.
Thread context used as proof
The message relies on genuine past details while resisting the established callback or approval process.
03Safe response
Move from suspicion to a supported next step
| Moment | Employee action | Program preparation |
|---|---|---|
| Before acting | Confirm consequential requests using the known directory, supplier record, or another approved channel that does not depend on the same mailbox. | Publish the authentic contact, application, or reporting route somewhere employees can reach without using the message. |
| When uncertain | Pause the request and report it through the approved channel with enough context for review. | Explain what the response team needs and how employees will know that their report was received. |
| After an interaction | Stop, contact the responsible team promptly, and describe the action taken without hiding the mistake. | Provide a well-known response route and avoid communications that discourage early reporting. |
Source: NIST: Recognizing, verifying, and reporting phishing
04Practice safely
Email Account Compromise simulation and discussion ideas
Choose one learning objective per exercise. Use fictional people, organizations, accounts, payments, documents, and events, and test the reporting route before sending to employees.
Familiar supplier mailbox
Use an invented vendor conversation that introduces a new payment destination and requires independent confirmation.
Colleague document request
Practice verifying an unusual sensitive-file request sent from a known fictional coworker account.
Mailbox warning tabletop
Rehearse reporting unexplained rules, forwarding, sent messages, or authentication activity.
05Campaign workflow
Build the exercise around a decision employees can repeat
- 1
Define the behavior
Write down the email account compromise clue being practiced, the expected action, the authorized audience, and the owner of follow-up.
- 2
Confirm the real process
Test the independent verification route, message-reporting option, response handoff, and employee support path from a representative account.
- 3
Pilot the scenario
Check delivery, links, landing content, accessibility, event records, automated inspection, stop conditions, and the explanation employees will receive.
- 4
Review in context
Reconcile intended recipients, successful deliveries, unique employee events, verified reports, response handling, and completed follow-up before drawing conclusions.
Source: NIST SP 800-50 Rev. 1: Building a Cybersecurity and Privacy Learning Program
06Useful measurement
Evaluate recognition, reporting, and the surrounding process
Record actual counts and denominators for delivery, unique recipient events, reports, and follow-up. Separate automated email inspection and repeat events where the available evidence supports doing so.
A email account compromise exercise samples one scenario under one set of conditions. It does not establish an employee's intent, overall security awareness, or likelihood of responding the same way to a real attack.
Use findings to improve the real workflow: clearer verification instructions, easier reporting, faster response handling, better role-specific training, or a business control that reduces reliance on email alone.
Common questions
Common questions about Phishmake's features, onboarding, and support, answered to help you get started with confidence.
Can a compromised email pass authentication checks?
A message sent through a real account may look technically legitimate. Business verification controls remain important for consequential actions.
What is the employee's role?
Employees should recognize unexpected account activity or unusual requests and report promptly. Investigation and containment belong to the authorized response team.
Can email account compromise be used in a phishing simulation?
It can be practiced when the scenario is authorized, proportionate, and tied to a real reporting or verification process. Do not enter, modify, or simulate compromise of a real mailbox. Use controlled test accounts or fictional examples and keep production messages and settings unchanged.
How should email account compromise simulation results be measured?
Review successful delivery, unique employee events, reports, response handling, and completed follow-up. Include scenario difficulty and operating context, and do not treat a click or report as a complete measure of employee risk.
Sources & further reading
Published by Phishmake · Updated
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Turn email account compromise awareness into a repeatable response.
Use Phishmake to run controlled employee simulations, review campaign activity, assign relevant training, and keep follow-up records in one workflow.